The Caboose Who Got Loose is a children's picture book written and illustrated by Bill Peet.The Caboose Who Got Loose, published in 1971 by Houghton Mifflin, tells the story of Katy Caboose, a caboose who is tired of being dragged around at the end of the train by the Engine. She dreams of being part of the beautiful sceneries she passes during her trips, but she cannot because she is always on the move.